ContactPane: move internal widgets to ContactEditor
ContactEditor: use Button.from_icon_name
AvatarDialog: updated UI

Made compliant with dialog guidelines for GNOME

Fixed: https://bugzilla.gnome.org/show_bug.cgi?id=675652
misc: move ::change_avatar to ContactEditor source

This was previously misplaced, now, with the cleaning you can tell easily.
ContactEditor: fixed memory corruption
ContactEditor: initial work to provide inline contact creation

Changed widget so it can work when no contact/persona is set
misc: API change to maintain readability
ContactEditor: tweak inline contact template
ContactPane: provide API to handle inline contact creation

This will be used from Window till we can remove all the logic from ContactPane
ContactPane: fix leave edit-mode when no contact is set
Window: provide entry point for inline contact creation

Hook into ContactPane new API.
Adjust leave edit-mode behavior so it can cancel contact creation
ContactPane: added commit new contact code

Missing avatar handling since more code has to change for that to work
Window: fix leave edit-mode behavior
App: hooked Ctrl+n to new contact creation mode

Fixed function name in Contacts.Window, reordered
ContactEditor: clear also unset internal contact
AvatarDialog: make it not require a contact

In order to use it for new contact creation AvatarDialog could not
require a contact since there's none yet when you're are creating one
ContactEditor: make avatar regular detail

Added methods for knowing when the avatar has changed and for retrieving
the new value.
ContactPane: commit avatar changes when editing or creating

With this commit ends the work on inline contact creation
Fixed: https://bugzilla.gnome.org/show_bug.cgi?id=699324
build: remove unused code
build: fixed dist